//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:  none
//

#include <string.h>
#include <stdlib.h>
#include <math.h>

#include "doomdef.h"
#include "doomkeys.h"
#include "doomstat.h"

#include "deh_main.h"
#include "deh_misc.h"

#include "z_zone.h"
#include "f_finale.h"
#include "m_argv.h"
#include "m_controls.h"
#include "m_misc.h"
#include "m_menu.h"
#include "m_random.h"
#include "i_system.h"
#include "i_timer.h"
#include "i_video.h"

#include "p_setup.h"
#include "p_saveg.h"
#include "p_tick.h"

#include "d_main.h"

#include "wi_stuff.h"
#include "hu_stuff.h"
#include "st_stuff.h"
#include "am_map.h"
#include "statdump.h"

// Needs access to LFB.
#include "v_video.h"

#include "w_wad.h"

#include "p_local.h"

#include "s_sound.h"

// Data.
#include "dstrings.h"
#include "sounds.h"

// SKY handling - still the wrong place.
#include "r_data.h"
#include "r_sky.h"

#include "g_game.h"


#define SAVEGAMESIZE    0x2c000

void    G_ReadDemoTiccmd (ticcmd_t* cmd);
void    G_WriteDemoTiccmd (ticcmd_t* cmd);
void    G_PlayerReborn (int player);

void    G_DoReborn (int playernum);

void    G_DoLoadLevel (void);
void    G_DoNewGame (void);
void    G_DoPlayDemo (void);
void    G_DoCompleted (void);
void    G_DoVictory (void);
void    G_DoWorldDone (void);
void    G_DoSaveGame (void);

// Gamestate the last time G_Ticker was called.

gamestate_t     oldgamestate;

gameaction_t    gameaction;
gamestate_t     gamestate;
skill_t         gameskill;
boolean     respawnmonsters;
int             gameepisode;
int             gamemap;

// If non-zero, exit the level after this number of minutes.

int             timelimit;

boolean         paused;
boolean         sendpause;              // send a pause event next tic
boolean         sendsave;               // send a save event next tic
boolean         usergame;               // ok to save / end game

boolean         timingdemo;             // if true, exit with report on completion
boolean         nodrawers;              // for comparative timing purposes
int             starttime;              // for comparative timing purposes

boolean         viewactive;

int             deathmatch;             // only if started as net death
boolean         netgame;                // only true if packets are broadcast
boolean         playeringame[MAXPLAYERS];
player_t        players[MAXPLAYERS];

boolean         turbodetected[MAXPLAYERS];

int             consoleplayer;          // player taking events and displaying
int             displayplayer;          // view being displayed
int             levelstarttic;          // gametic at level start
int             totalkills, totalitems, totalsecret;    // for intermission

char           *demoname;
boolean         demorecording;
boolean         longtics;               // cph's doom 1.91 longtics hack
boolean         lowres_turn;            // low resolution turning for longtics
boolean         demoplayback;
boolean     netdemo;
byte*       demobuffer;
byte*       demo_p;
byte*       demoend;
boolean         singledemo;             // quit after playing a demo from cmdline

boolean         precache = true;        // if true, load all graphics at start

boolean         testcontrols = false;    // Invoked by setup to test controls
int             testcontrols_mousespeed;



wbstartstruct_t wminfo;                 // parms for world map / intermission

byte        consistancy[MAXPLAYERS][BACKUPTICS];

#define MAXPLMOVE       (forwardmove[1])

#define TURBOTHRESHOLD  0x32

fixed_t         forwardmove[2] = {0x19, 0x32};
fixed_t         sidemove[2] = {0x18, 0x28};
fixed_t         angleturn[3] = {640, 1280, 320};    // + slow turn

static int *weapon_keys[] = {
    &key_weapon1,
    &key_weapon2,
    &key_weapon3,
    &key_weapon4,
    &key_weapon5,
    &key_weapon6,
    &key_weapon7,
    &key_weapon8
};

// Set to -1 or +1 to switch to the previous or next weapon.

static int next_weapon = 0;

// Used for prev/next weapon keys.

static const struct
{
    weapontype_t weapon;
    weapontype_t weapon_num;
} weapon_order_table[] = {
    { wp_fist,            wp_fist },
    { wp_chainsaw,        wp_fist },
    { wp_pistol,          wp_pistol },
    { wp_shotgun,         wp_shotgun },
    { wp_supershotgun,    wp_shotgun },
    { wp_chaingun,        wp_chaingun },
    { wp_missile,         wp_missile },
    { wp_plasma,          wp_plasma },
    { wp_bfg,             wp_bfg }
};

#define SLOWTURNTICS    6

#define NUMKEYS     256
#define MAX_JOY_BUTTONS 20

static boolean  gamekeydown[NUMKEYS];
static int      turnheld;       // for accelerative turning

static boolean  mousearray[MAX_MOUSE_BUTTONS + 1];
static boolean *mousebuttons = &mousearray[1];  // allow [-1]

// mouse values are used once
int             mousex;
int             mousey;

static int      dclicktime;
static boolean  dclickstate;
static int      dclicks;
static int      dclicktime2;
static boolean  dclickstate2;
static int      dclicks2;

// joystick values are repeated
static int      joyxmove;
static int      joyymove;
static int      joystrafemove;
static boolean  joyarray[MAX_JOY_BUTTONS + 1];
static boolean *joybuttons = &joyarray[1];      // allow [-1]

static int      savegameslot;
static char     savedescription[32];

#define BODYQUESIZE 32

mobj_t*     bodyque[BODYQUESIZE];
int     bodyqueslot;

int             vanilla_savegame_limit = 1;
int             vanilla_demo_limit = 1;

int G_CmdChecksum (ticcmd_t* cmd)
{
    size_t      i;
    int     sum = 0;

    for (i=0 ; i< sizeof(*cmd)/4 - 1 ; i++)
    sum += ((int *)cmd)[i];

    return sum;
}

static boolean WeaponSelectable(weapontype_t weapon)
{
    // Can't select the super shotgun in Doom 1.

    if (weapon == wp_supershotgun && logical_gamemission == doom)
    {
        return false;
    }

    // These weapons aren't available in shareware.

    if ((weapon == wp_plasma || weapon == wp_bfg)
     && gamemission == doom && gamemode == shareware)
    {
        return false;
    }

    // Can't select a weapon if we don't own it.

    if (!players[consoleplayer].weaponowned[weapon])
    {
        return false;
    }

    // Can't select the fist if we have the chainsaw, unless
    // we also have the berserk pack.

    if (weapon == wp_fist
     && players[consoleplayer].weaponowned[wp_chainsaw]
     && !players[consoleplayer].powers[pw_strength])
    {
        return false;
    }

    return true;
}

static int G_NextWeapon(int direction)
{
    weapontype_t weapon;
    int i;

    // Find index in the table.

    if (players[consoleplayer].pendingweapon == wp_nochange)
    {
        weapon = players[consoleplayer].readyweapon;
    }
    else
    {
        weapon = players[consoleplayer].pendingweapon;
    }

    for (i=0; i<arrlen(weapon_order_table); ++i)
    {
        if (weapon_order_table[i].weapon == weapon)
        {
            break;
        }
    }

    // Switch weapon.

    do
    {
        i += direction;
        i = (i + arrlen(weapon_order_table)) % arrlen(weapon_order_table);
    } while (!WeaponSelectable(weapon_order_table[i].weapon));

    return weapon_order_table[i].weapon_num;
}

//
// G_BuildTiccmd
// Builds a ticcmd from all of the available inputs
// or reads it from the demo buffer.
// If recording a demo, write it out
//
void G_BuildTiccmd (ticcmd_t* cmd, int maketic)
{
    int     i;
    boolean strafe;
    boolean bstrafe;
    int     speed;
    int     tspeed;
    int     forward;
    int     side;

    memset(cmd, 0, sizeof(ticcmd_t));

    cmd->consistancy =
    consistancy[consoleplayer][maketic%BACKUPTICS];

    strafe = gamekeydown[key_strafe] || mousebuttons[mousebstrafe]
    || joybuttons[joybstrafe];

    // fraggle: support the old "joyb_speed = 31" hack which
    // allowed an autorun effect

    speed = key_speed >= NUMKEYS
         || joybspeed >= MAX_JOY_BUTTONS
         || gamekeydown[key_speed]
         || joybuttons[joybspeed];

    forward = side = 0;

    // use two stage accelerative turning
    // on the keyboard and joystick
    if (joyxmove < 0
    || joyxmove > 0
    || gamekeydown[key_right]
    || gamekeydown[key_left])
    turnheld += ticdup;
    else
    turnheld = 0;

    if (turnheld < SLOWTURNTICS)
    tspeed = 2;             // slow turn
    else
    tspeed = speed;

    // let movement keys cancel each other out
    if (strafe)
    {
    if (gamekeydown[key_right])
    {
        // fprintf(stderr, "strafe right\n");
        side += sidemove[speed];
    }
    if (gamekeydown[key_left])
    {
        //  fprintf(stderr, "strafe left\n");
        side -= sidemove[speed];
    }
    if (joyxmove > 0)
        side += sidemove[speed];
    if (joyxmove < 0)
        side -= sidemove[speed];

    }
    else
    {
    if (gamekeydown[key_right])
        cmd->angleturn -= angleturn[tspeed];
    if (gamekeydown[key_left])
        cmd->angleturn += angleturn[tspeed];
    if (joyxmove > 0)
        cmd->angleturn -= angleturn[tspeed];
    if (joyxmove < 0)
        cmd->angleturn += angleturn[tspeed];
    }

    if (gamekeydown[key_up])
    {
    // fprintf(stderr, "up\n");
    forward += forwardmove[speed];
    }
    if (gamekeydown[key_down])
    {
    // fprintf(stderr, "down\n");
    forward -= forwardmove[speed];
    }

    if (joyymove < 0)
        forward += forwardmove[speed];
    if (joyymove > 0)
        forward -= forwardmove[speed];

    if (gamekeydown[key_strafeleft]
     || joybuttons[joybstrafeleft]
     || mousebuttons[mousebstrafeleft]
     || joystrafemove < 0)
    {
        side -= sidemove[speed];
    }

    if (gamekeydown[key_straferight]
     || joybuttons[joybstraferight]
     || mousebuttons[mousebstraferight]
     || joystrafemove > 0)
    {
        side += sidemove[speed];
    }

    // buttons
    cmd->chatchar = HU_dequeueChatChar();

    if (gamekeydown[key_fire] || mousebuttons[mousebfire]
    || joybuttons[joybfire])
    cmd->buttons |= BT_ATTACK;

    if (gamekeydown[key_use]
     || joybuttons[joybuse]
     || mousebuttons[mousebuse])
    {
    cmd->buttons |= BT_USE;
    // clear double clicks if hit use button
    dclicks = 0;
    }

    // If the previous or next weapon button is pressed, the
    // next_weapon variable is set to change weapons when
    // we generate a ticcmd.  Choose a new weapon.

    if (next_weapon != 0)
    {
        i = G_NextWeapon(next_weapon);
        cmd->buttons |= BT_CHANGE;
        cmd->buttons |= i << BT_WEAPONSHIFT;
        next_weapon = 0;
    }
    else
    {
        // Check weapon keys.

        for (i=0; i<arrlen(weapon_keys); ++i)
        {
            int key = *weapon_keys[i];

            if (gamekeydown[key])
            {
                cmd->buttons |= BT_CHANGE;
                cmd->buttons |= i<<BT_WEAPONSHIFT;
                break;
            }
        }
    }

    // mouse
    if (mousebuttons[mousebforward])
    {
    forward += forwardmove[speed];
    }
    if (mousebuttons[mousebbackward])
    {
        forward -= forwardmove[speed];
    }

    if (dclick_use)
    {
        // forward double click
        if (mousebuttons[mousebforward] != dclickstate && dclicktime > 1 )
        {
            dclickstate = mousebuttons[mousebforward];
            if (dclickstate)
                dclicks++;
            if (dclicks == 2)
            {
                cmd->buttons |= BT_USE;
                dclicks = 0;
            }
            else
                dclicktime = 0;
        }
        else
        {
            dclicktime += ticdup;
            if (dclicktime > 20)
            {
                dclicks = 0;
                dclickstate = 0;
            }
        }

        // strafe double click
        bstrafe =
            mousebuttons[mousebstrafe]
            || joybuttons[joybstrafe];
        if (bstrafe != dclickstate2 && dclicktime2 > 1 )
        {
            dclickstate2 = bstrafe;
            if (dclickstate2)
                dclicks2++;
            if (dclicks2 == 2)
            {
                cmd->buttons |= BT_USE;
                dclicks2 = 0;
            }
            else
                dclicktime2 = 0;
        }
        else
        {
            dclicktime2 += ticdup;
            if (dclicktime2 > 20)
            {
                dclicks2 = 0;
                dclickstate2 = 0;
            }
        }
    }

    forward += mousey;

    if (strafe)
    side += mousex*2;
    else
    cmd->angleturn -= mousex*0x8;

    if (mousex == 0)
    {
        // No movement in the previous frame

        testcontrols_mousespeed = 0;
    }

    mousex = mousey = 0;

    if (forward > MAXPLMOVE)
    forward = MAXPLMOVE;
    else if (forward < -MAXPLMOVE)
    forward = -MAXPLMOVE;
    if (side > MAXPLMOVE)
    side = MAXPLMOVE;
    else if (side < -MAXPLMOVE)
    side = -MAXPLMOVE;

    cmd->forwardmove += forward;
    cmd->sidemove += side;

    // special buttons
    if (sendpause)
    {
    sendpause = false;
    cmd->buttons = BT_SPECIAL | BTS_PAUSE;
    }

    if (sendsave)
    {
    sendsave = false;
    cmd->buttons = BT_SPECIAL | BTS_SAVEGAME | (savegameslot<<BTS_SAVESHIFT);
    }

    // low-res turning

    if (lowres_turn)
    {
        static signed short carry = 0;
        signed short desired_angleturn;

        desired_angleturn = cmd->angleturn + carry;

        // round angleturn to the nearest 256 unit boundary
        // for recording demos with single byte values for turn

        cmd->angleturn = (desired_angleturn + 128) & 0xff00;

        // Carry forward the error from the reduced resolution to the
        // next tic, so that successive small movements can accumulate.

        carry = desired_angleturn - cmd->angleturn;
    }
}


//
// G_DoLoadLevel
//
void G_DoLoadLevel (void)
{
    int             i;

    // Set the sky map.
    // First thing, we have a dummy sky texture name,
    //  a flat. The data is in the WAD only because
    //  we look for an actual index, instead of simply
    //  setting one.

    skyflatnum = R_FlatNumForName(DEH_String(SKYFLATNAME));

    levelstarttic = gametic;        // for time calculation

    if (wipegamestate == GS_LEVEL)
    wipegamestate = -1;             // force a wipe

    gamestate = GS_LEVEL;

    for (i=0 ; i<MAXPLAYERS ; i++)
    {
    turbodetected[i] = false;
    if (playeringame[i] && players[i].playerstate == PST_DEAD)
        players[i].playerstate = PST_REBORN;
    memset (players[i].frags,0,sizeof(players[i].frags));
    }

    P_SetupLevel (gameepisode, gamemap, 0, gameskill);
    displayplayer = consoleplayer;      // view the guy you are playing
    gameaction = ga_nothing;
    Z_CheckHeap ();

    // clear cmd building stuff

    memset (gamekeydown, 0, sizeof(gamekeydown));
    joyxmove = joyymove = joystrafemove = 0;
    mousex = mousey = 0;
    sendpause = sendsave = paused = false;
    memset(mousearray, 0, sizeof(mousearray));
    memset(joyarray, 0, sizeof(joyarray));

    if (testcontrols)
    {
        players[consoleplayer].message = "Press escape to quit.";
    }
}

static void SetJoyButtons(unsigned int buttons_mask)
{
    int i;

    for (i=0; i<MAX_JOY_BUTTONS; ++i)
    {
        int button_on = (buttons_mask & (1 << i)) != 0;

        // Detect button press:

        if (!joybuttons[i] && button_on)
        {
            // Weapon cycling:

            if (i == joybprevweapon)
            {
                next_weapon = -1;
            }
            else if (i == joybnextweapon)
            {
                next_weapon = 1;
            }
        }

        joybuttons[i] = button_on;
    }
}

static void SetMouseButtons(unsigned int buttons_mask)
{
    int i;

    for (i=0; i<MAX_MOUSE_BUTTONS; ++i)
    {
        unsigned int button_on = (buttons_mask & (1 << i)) != 0;

        // Detect button press:

        if (!mousebuttons[i] && button_on)
        {
            if (i == mousebprevweapon)
            {
                next_weapon = -1;
            }
            else if (i == mousebnextweapon)
            {
                next_weapon = 1;
            }
        }

    mousebuttons[i] = button_on;
    }
}

//
// G_Responder
// Get info needed to make ticcmd_ts for the players.
//
boolean G_Responder (event_t* ev)
{
    // allow spy mode changes even during the demo
    if (gamestate == GS_LEVEL && ev->type == ev_keydown
     && ev->data1 == key_spy && (singledemo || !deathmatch) )
    {
    // spy mode
    do
    {
        displayplayer++;
        if (displayplayer == MAXPLAYERS)
        displayplayer = 0;
    } while (!playeringame[displayplayer] && displayplayer != consoleplayer);
    return true;
    }

    // any other key pops up menu if in demos
    if (gameaction == ga_nothing && !singledemo &&
    (demoplayback || gamestate == GS_DEMOSCREEN)
    )
    {
    if (ev->type == ev_keydown ||
        (ev->type == ev_mouse && ev->data1) ||
        (ev->type == ev_joystick && ev->data1) )
    {
        M_StartControlPanel ();
        return true;
    }
    return false;
    }

    if (gamestate == GS_LEVEL)
    {
#if 0
    if (devparm && ev->type == ev_keydown && ev->data1 == ';')
    {
        G_DeathMatchSpawnPlayer (0);
        return true;
    }
#endif
    if (HU_Responder (ev))
        return true;    // chat ate the event
    if (ST_Responder (ev))
        return true;    // status window ate it
    if (AM_Responder (ev))
        return true;    // automap ate it
    }

    if (gamestate == GS_FINALE)
    {
    if (F_Responder (ev))
        return true;    // finale ate the event
    }

    if (testcontrols && ev->type == ev_mouse)
    {
        // If we are invoked by setup to test the controls, save the
        // mouse speed so that we can display it on-screen.
        // Perform a low pass filter on this so that the thermometer
        // appears to move smoothly.

        testcontrols_mousespeed = abs(ev->data2);
    }

    // If the next/previous weapon keys are pressed, set the next_weapon
    // variable to change weapons when the next ticcmd is generated.

    if (ev->type == ev_keydown && ev->data1 == key_prevweapon)
    {
        next_weapon = -1;
    }
    else if (ev->type == ev_keydown && ev->data1 == key_nextweapon)
    {
        next_weapon = 1;
    }

    switch (ev->type)
    {
      case ev_keydown:
    if (ev->data1 == key_pause)
    {
        sendpause = true;
    }
        else if (ev->data1 <NUMKEYS)
        {
        gamekeydown[ev->data1] = true;
        }

    return true;    // eat key down events

      case ev_keyup:
    if (ev->data1 <NUMKEYS)
        gamekeydown[ev->data1] = false;
    return false;   // always let key up events filter down

      case ev_mouse:
        SetMouseButtons(ev->data1);
    mousex = ev->data2*(mouseSensitivity+5)/10;
    mousey = ev->data3*(mouseSensitivity+5)/10;
    return true;    // eat events

      case ev_joystick:
        SetJoyButtons(ev->data1);
    joyxmove = ev->data2;
    joyymove = ev->data3;
        joystrafemove = ev->data4;
    return true;    // eat events

      default:
    break;
    }

    return false;
}



//
// G_Ticker
// Make ticcmd_ts for the players.
//
void G_Ticker (void)
{
    int     i;
    int     buf;
    ticcmd_t*   cmd;

    // do player reborns if needed
    for (i=0 ; i<MAXPLAYERS ; i++)
    if (playeringame[i] && players[i].playerstate == PST_REBORN)
        G_DoReborn (i);

    // do things to change the game state
    while (gameaction != ga_nothing)
    {
    switch (gameaction)
    {
      case ga_loadlevel:
        G_DoLoadLevel ();
        break;
      case ga_newgame:
        G_DoNewGame ();
        break;
      case ga_loadgame:
        G_DoLoadGame ();
        break;
      case ga_savegame:
        G_DoSaveGame ();
        break;
      case ga_playdemo:
        G_DoPlayDemo ();
        break;
      case ga_completed:
        G_DoCompleted ();
        break;
      case ga_victory:
        F_StartFinale ();
        break;
      case ga_worlddone:
        G_DoWorldDone ();
        break;
      case ga_screenshot:
        V_ScreenShot("DOOM%02i.%s");
            players[consoleplayer].message = DEH_String("screen shot");
        gameaction = ga_nothing;
        break;
      case ga_nothing:
        break;
    }
    }

    // get commands, check consistancy,
    // and build new consistancy check
    buf = (gametic/ticdup)%BACKUPTICS;

    for (i=0 ; i<MAXPLAYERS ; i++)
    {
    if (playeringame[i])
    {
        cmd = &players[i].cmd;

        memcpy(cmd, &netcmds[i], sizeof(ticcmd_t));

        if (demoplayback)
        G_ReadDemoTiccmd (cmd);
        if (demorecording)
        G_WriteDemoTiccmd (cmd);

        // check for turbo cheats

            // check ~ 4 seconds whether to display the turbo message.
            // store if the turbo threshold was exceeded in any tics
            // over the past 4 seconds.  offset the checking period
            // for each player so messages are not displayed at the
            // same time.

            if (cmd->forwardmove > TURBOTHRESHOLD)
            {
                turbodetected[i] = true;
            }

            if ((gametic & 31) == 0
             && ((gametic >> 5) % MAXPLAYERS) == i
             && turbodetected[i])
            {
                static char turbomessage[80];
                extern char *player_names[4];
                M_snprintf(turbomessage, sizeof(turbomessage),
                           "%s is turbo!", player_names[i]);
                players[consoleplayer].message = turbomessage;
                turbodetected[i] = false;
            }

        if (netgame && !netdemo && !(gametic%ticdup) )
        {
        if (gametic > BACKUPTICS
            && consistancy[i][buf] != cmd->consistancy)
        {
            I_Error ("consistency failure (%i should be %i)",
                 cmd->consistancy, consistancy[i][buf]);
        }
        if (players[i].mo)
            consistancy[i][buf] = players[i].mo->x;
        else
            consistancy[i][buf] = rndindex;
        }
    }
    }

    // check for special buttons
    for (i=0 ; i<MAXPLAYERS ; i++)
    {
    if (playeringame[i])
    {
        if (players[i].cmd.buttons & BT_SPECIAL)
        {
        switch (players[i].cmd.buttons & BT_SPECIALMASK)
        {
          case BTS_PAUSE:
            paused ^= 1;
            if (paused)
            S_PauseSound ();
            else
            S_ResumeSound ();
            break;

          case BTS_SAVEGAME:
            if (!savedescription[0])
                    {
                        M_StringCopy(savedescription, "NET GAME",
                                     sizeof(savedescription));
                    }

            savegameslot =
            (players[i].cmd.buttons & BTS_SAVEMASK)>>BTS_SAVESHIFT;
            gameaction = ga_savegame;
            break;
        }
        }
    }
    }

    // Have we just finished displaying an intermission screen?

    if (oldgamestate == GS_INTERMISSION && gamestate != GS_INTERMISSION)
    {
        WI_End();
    }

    oldgamestate = gamestate;

    // do main actions
    switch (gamestate)
    {
      case GS_LEVEL:
    P_Ticker ();
    ST_Ticker ();
    AM_Ticker ();
    HU_Ticker ();
    break;

      case GS_INTERMISSION:
    WI_Ticker ();
    break;

      case GS_FINALE:
    F_Ticker ();
    break;

      case GS_DEMOSCREEN:
    D_PageTicker ();
    break;
    }
}


//
// PLAYER STRUCTURE FUNCTIONS
// also see P_SpawnPlayer in P_Things
//

//
// G_InitPlayer
// Called at the start.
// Called by the game initialization functions.
//
void G_InitPlayer (int player)
{
    // clear everything else to defaults
    G_PlayerReborn (player);
}



//
// G_PlayerFinishLevel
// Can when a player completes a level.
//
void G_PlayerFinishLevel (int player)
{
    player_t*   p;

    p = &players[player];

    memset (p->powers, 0, sizeof (p->powers));
    memset (p->cards, 0, sizeof (p->cards));
    p->mo->flags &= ~MF_SHADOW;     // cancel invisibility
    p->extralight = 0;          // cancel gun flashes
    p->fixedcolormap = 0;       // cancel ir gogles
    p->damagecount = 0;         // no palette changes
    p->bonuscount = 0;
}


//
// G_PlayerReborn
// Called after a player dies
// almost everything is cleared and initialized
//
void G_PlayerReborn (int player)
{
    player_t*   p;
    int     i;
    int     frags[MAXPLAYERS];
    int     killcount;
    int     itemcount;
    int     secretcount;

    memcpy (frags,players[player].frags,sizeof(frags));
    killcount = players[player].killcount;
    itemcount = players[player].itemcount;
    secretcount = players[player].secretcount;

    p = &players[player];
    memset (p, 0, sizeof(*p));

    memcpy (players[player].frags, frags, sizeof(players[player].frags));
    players[player].killcount = killcount;
    players[player].itemcount = itemcount;
    players[player].secretcount = secretcount;

    p->usedown = p->attackdown = true;  // don't do anything immediately
    p->playerstate = PST_LIVE;
    p->health = deh_initial_health;     // Use dehacked value
    p->readyweapon = p->pendingweapon = wp_pistol;
    p->weaponowned[wp_fist] = true;
    p->weaponowned[wp_pistol] = true;
    p->ammo[am_clip] = deh_initial_bullets;

    for (i=0 ; i<NUMAMMO ; i++)
    p->maxammo[i] = maxammo[i];

}

//
// G_CheckSpot
// Returns false if the player cannot be respawned
// at the given mapthing_t spot
// because something is occupying it
//
void P_SpawnPlayer (mapthing_t* mthing);

boolean
G_CheckSpot
( int       playernum,
  mapthing_t*   mthing )
{
    fixed_t     x;
    fixed_t     y;
    subsector_t*    ss;
    mobj_t*     mo;
    int         i;

    if (!players[playernum].mo)
    {
    // first spawn of level, before corpses
    for (i=0 ; i<playernum ; i++)
        if (players[i].mo->x == mthing->x << FRACBITS
        && players[i].mo->y == mthing->y << FRACBITS)
        return false;
    return true;
    }

    x = mthing->x << FRACBITS;
    y = mthing->y << FRACBITS;

    if (!P_CheckPosition (players[playernum].mo, x, y) )
    return false;

    // flush an old corpse if needed
    if (bodyqueslot >= BODYQUESIZE)
    P_RemoveMobj (bodyque[bodyqueslot%BODYQUESIZE]);
    bodyque[bodyqueslot%BODYQUESIZE] = players[playernum].mo;
    bodyqueslot++;

    // spawn a teleport fog
    ss = R_PointInSubsector (x,y);


    // The code in the released source looks like this:
    //
    //    an = ( ANG45 * (((unsigned int) mthing->angle)/45) )
    //         >> ANGLETOFINESHIFT;
    //    mo = P_SpawnMobj (x+20*finecosine[an], y+20*finesine[an]
    //                     , ss->sector->floorheight
    //                     , MT_TFOG);
    //
    // But 'an' can be a signed value in the DOS version. This means that
    // we get a negative index and the lookups into finecosine/finesine
    // end up dereferencing values in finetangent[].
    // A player spawning on a deathmatch start facing directly west spawns
    // "silently" with no spawn fog. Emulate this.
    //
    // This code is imported from PrBoom+.

    {
        fixed_t xa, ya;
        signed int an;

        an = (ANG45 * ((signed int) mthing->angle / 45));
        // Right-shifting a negative signed integer is implementation-defined,
        // so divide instead.
        an /= 1 << ANGLETOFINESHIFT;

        switch (an)
        {
            case -4096:
                xa = finetangent[2048];    // finecosine[-4096]
                ya = finetangent[0];       // finesine[-4096]
                break;
            case -3072:
                xa = finetangent[3072];    // finecosine[-3072]
                ya = finetangent[1024];    // finesine[-3072]
                break;
            case -2048:
                xa = finesine[0];          // finecosine[-2048]
                ya = finetangent[2048];    // finesine[-2048]
                break;
            case -1024:
                xa = finesine[1024];       // finecosine[-1024]
                ya = finetangent[3072];    // finesine[-1024]
                break;
            case 0:
            case 1024:
            case 2048:
            case 3072:
            case 4096:
                xa = finecosine[an];
                ya = finesine[an];
                break;
            default:
                I_Error("G_CheckSpot: unexpected angle %d\n", an);
                xa = ya = 0;
                break;
        }
        mo = P_SpawnMobj(x + 20 * xa, y + 20 * ya,
                         ss->sector->floorheight, MT_TFOG);
    }

    if (players[consoleplayer].viewz != 1)
    S_StartSound (mo, sfx_telept);  // don't start sound on first frame

    return true;
}


//
// G_DeathMatchSpawnPlayer
// Spawns a player at one of the random death match spots
// called at level load and each death
//
void G_DeathMatchSpawnPlayer (int playernum)
{
    int             i,j;
    int             selections;

    selections = deathmatch_p - deathmatchstarts;
    if (selections < 4)
    I_Error ("Only %i deathmatch spots, 4 required", selections);

    for (j=0 ; j<20 ; j++)
    {
    i = P_Random() % selections;
    if (G_CheckSpot (playernum, &deathmatchstarts[i]) )
    {
        deathmatchstarts[i].type = playernum+1;
        P_SpawnPlayer (&deathmatchstarts[i]);
        return;
    }
    }

    // no good spot, so the player will probably get stuck
    P_SpawnPlayer (&playerstarts[playernum]);
}

//
// G_DoReborn
//
void G_DoReborn (int playernum)
{
    int                             i;

    if (!netgame)
    {
    // reload the level from scratch
    gameaction = ga_loadlevel;
    }
    else
    {
    // respawn at the start

    // first dissasociate the corpse
    players[playernum].mo->player = NULL;

    // spawn at random spot if in death match
    if (deathmatch)
    {
        G_DeathMatchSpawnPlayer (playernum);
        return;
    }

    if (G_CheckSpot (playernum, &playerstarts[playernum]) )
    {
        P_SpawnPlayer (&playerstarts[playernum]);
        return;
    }

    // try to spawn at one of the other players spots
    for (i=0 ; i<MAXPLAYERS ; i++)
    {
        if (G_CheckSpot (playernum, &playerstarts[i]) )
        {
        playerstarts[i].type = playernum+1; // fake as other player
        P_SpawnPlayer (&playerstarts[i]);
        playerstarts[i].type = i+1;     // restore
        return;
        }
        // he's going to be inside something.  Too bad.
    }
    P_SpawnPlayer (&playerstarts[playernum]);
    }
}


void G_ScreenShot (void)
{
    gameaction = ga_screenshot;
}



// DOOM Par Times
int pars[4][10] =
{
    {0},
    {0,30,75,120,90,165,180,180,30,165},
    {0,90,90,90,120,90,360,240,30,170},
    {0,90,45,90,150,90,90,165,30,135}
};

// DOOM II Par Times
int cpars[32] =
{
    30,90,120,120,90,150,120,120,270,90,    //  1-10
    210,150,150,150,210,150,420,150,210,150,    // 11-20
    240,150,180,150,150,300,330,420,300,180,    // 21-30
    120,30                  // 31-32
};


//
// G_DoCompleted
//
boolean     secretexit;
extern char*    pagename;

void G_ExitLevel (void)
{
    secretexit = false;
    gameaction = ga_completed;
}

// Here's for the german edition.
void G_SecretExitLevel (void)
{
    // IF NO WOLF3D LEVELS, NO SECRET EXIT!
    if ( (gamemode == commercial)
      && (W_CheckNumForName("map31")<0))
    secretexit = false;
    else
    secretexit = true;
    gameaction = ga_completed;
}

void G_DoCompleted (void)
{
    int             i;

    gameaction = ga_nothing;

    for (i=0 ; i<MAXPLAYERS ; i++)
    if (playeringame[i])
        G_PlayerFinishLevel (i);        // take away cards and stuff

    if (automapactive)
    AM_Stop ();

    if (gamemode != commercial)
    {
        // Chex Quest ends after 5 levels, rather than 8.

        if (gameversion == exe_chex)
        {
            if (gamemap == 5)
            {
                gameaction = ga_victory;
                return;
            }
        }
        else
        {
            switch(gamemap)
            {
              case 8:
                gameaction = ga_victory;
                return;
              case 9:
                for (i=0 ; i<MAXPLAYERS ; i++)
                    players[i].didsecret = true;
                break;
            }
        }
    }

//#if 0  Hmmm - why?
    if ( (gamemap == 8)
     && (gamemode != commercial) )
    {
    // victory
    gameaction = ga_victory;
    return;
    }

    if ( (gamemap == 9)
     && (gamemode != commercial) )
    {
    // exit secret level
    for (i=0 ; i<MAXPLAYERS ; i++)
        players[i].didsecret = true;
    }
//#endif


    wminfo.didsecret = players[consoleplayer].didsecret;
    wminfo.epsd = gameepisode -1;
    wminfo.last = gamemap -1;

    // wminfo.next is 0 biased, unlike gamemap
    if ( gamemode == commercial)
    {
    if (secretexit)
        switch(gamemap)
        {
          case 15: wminfo.next = 30; break;
          case 31: wminfo.next = 31; break;
        }
    else
        switch(gamemap)
        {
          case 31:
          case 32: wminfo.next = 15; break;
          default: wminfo.next = gamemap;
        }
    }
    else
    {
    if (secretexit)
        wminfo.next = 8;    // go to secret level
    else if (gamemap == 9)
    {
        // returning from secret level
        switch (gameepisode)
        {
          case 1:
        wminfo.next = 3;
        break;
          case 2:
        wminfo.next = 5;
        break;
          case 3:
        wminfo.next = 6;
        break;
          case 4:
        wminfo.next = 2;
        break;
        }
    }
    else
        wminfo.next = gamemap;          // go to next level
    }

    wminfo.maxkills = totalkills;
    wminfo.maxitems = totalitems;
    wminfo.maxsecret = totalsecret;
    wminfo.maxfrags = 0;

    // Set par time. Doom episode 4 doesn't have a par time, so this
    // overflows into the cpars array. It's necessary to emulate this
    // for statcheck regression testing.
    if (gamemode == commercial)
    wminfo.partime = TICRATE*cpars[gamemap-1];
    else if (gameepisode < 4)
    wminfo.partime = TICRATE*pars[gameepisode][gamemap];
    else
        wminfo.partime = TICRATE*cpars[gamemap];

    wminfo.pnum = consoleplayer;

    for (i=0 ; i<MAXPLAYERS ; i++)
    {
    wminfo.plyr[i].in = playeringame[i];
    wminfo.plyr[i].skills = players[i].killcount;
    wminfo.plyr[i].sitems = players[i].itemcount;
    wminfo.plyr[i].ssecret = players[i].secretcount;
    wminfo.plyr[i].stime = leveltime;
    memcpy (wminfo.plyr[i].frags, players[i].frags
        , sizeof(wminfo.plyr[i].frags));
    }

    gamestate = GS_INTERMISSION;
    viewactive = false;
    automapactive = false;

    StatCopy(&wminfo);

    WI_Start (&wminfo);
}


//
// G_WorldDone
//
void G_WorldDone (void)
{
    gameaction = ga_worlddone;

    if (secretexit)
    players[consoleplayer].didsecret = true;

    if ( gamemode == commercial )
    {
    switch (gamemap)
    {
      case 15:
      case 31:
        if (!secretexit)
        break;
      case 6:
      case 11:
      case 20:
      case 30:
        F_StartFinale ();
        break;
    }
    }
}

void G_DoWorldDone (void)
{
    gamestate = GS_LEVEL;
    gamemap = wminfo.next+1;
    G_DoLoadLevel ();
    gameaction = ga_nothing;
    viewactive = true;
}



//
// G_InitFromSavegame
// Can be called by the startup code or the menu task.
//
extern boolean setsizeneeded;
void R_ExecuteSetViewSize (void);

char    savename[256];

void G_LoadGame (char* name)
{
    M_StringCopy(savename, name, sizeof(savename));
    gameaction = ga_loadgame;
}

#define VERSIONSIZE     16


void G_DoLoadGame (void)
{
    int savedleveltime;

    gameaction = ga_nothing;

    if (f_open (&save_stream, savename, FA_OPEN_EXISTING | FA_READ) != FR_OK)
    {
        return;
    }

    savegame_error = false;

    if (!P_ReadSaveGameHeader())
    {
        f_close (&save_stream);
        return;
    }

    savedleveltime = leveltime;

    // load a base level
    G_InitNew (gameskill, gameepisode, gamemap);

    leveltime = savedleveltime;

    // dearchive all the modifications
    P_UnArchivePlayers ();
    P_UnArchiveWorld ();
    P_UnArchiveThinkers ();
    P_UnArchiveSpecials ();

    if (!P_ReadSaveGameEOF())
    I_Error ("Bad savegame");

    f_close (&save_stream);

    if (setsizeneeded)
        R_ExecuteSetViewSize ();

    // draw the pattern into the back screen
    R_FillBackScreen ();
}


//
// G_SaveGame
// Called by the menu task.
// Description is a 24 byte text string
//
void
G_SaveGame
( int   slot,
  char* description )
{
    savegameslot = slot;
    M_StringCopy(savedescription, description, sizeof(savedescription));
    sendsave = true;
}

char* _strupr_d(char* src)
{
    while (*src != '\0')
    {
        if (*src >= 'a' && *src <= 'z')
            *src -= 32;
        src++;
    }
    return src;
}

void G_DoSaveGame (void)
{
    char *savegame_file;
    char *temp_savegame_file;
    FRESULT res;

    temp_savegame_file = P_TempSaveGameFile();
    savegame_file = P_SaveGameFile(savegameslot);

    // Open the savegame file for writing.  We write to a temporary file
    // and then rename it at the end if it was successfully written.
    // This prevents an existing savegame from being overwritten by
    // a corrupted one, or if a savegame buffer overrun occurs.

    if (f_open (&save_stream, temp_savegame_file, FA_CREATE_ALWAYS | FA_WRITE) != FR_OK)
    {
        I_Error ("open err %s\n", temp_savegame_file);
    }

    savegame_error = false;

    P_WriteSaveGameHeader(savedescription);

    P_ArchivePlayers ();
    P_ArchiveWorld ();
    P_ArchiveThinkers ();
    P_ArchiveSpecials ();

    P_WriteSaveGameEOF();

    // Enforce the same savegame size limit as in Vanilla Doom,
    // except if the vanilla_savegame_limit setting is turned off.

    if (vanilla_savegame_limit && f_tell (&save_stream) > SAVEGAMESIZE)
    {
        I_Error ("Savegame buffer overrun");
    }

    // Finish up, close the savegame file.

    f_close (&save_stream);

    // Now rename the temporary savegame file to the actual savegame
    // file, overwriting the old savegame if there was one there.

    if (M_FileExists (savegame_file))
    {
        f_unlink (savegame_file);
    }

    res = f_rename (temp_savegame_file, savegame_file);

    if (res != FR_OK)
    {
        I_Error ("Savegame not renamed, res = %i", res);
    }

    gameaction = ga_nothing;
    M_StringCopy(savedescription, "", sizeof(savedescription));

    players[consoleplayer].message = DEH_String(GGSAVED);

    // draw the pattern into the back screen
    R_FillBackScreen ();
}


//
// G_InitNew
// Can be called by the startup code or the menu task,
// consoleplayer, displayplayer, playeringame[] should be set.
//
skill_t d_skill;
int     d_episode;
int     d_map;

void
G_DeferedInitNew
( skill_t   skill,
  int       episode,
  int       map)
{
    d_skill = skill;
    d_episode = episode;
    d_map = map;
    gameaction = ga_newgame;
}


void G_DoNewGame (void)
{
    demoplayback = false;
    netdemo = false;
    netgame = false;
    deathmatch = false;
    playeringame[1] = playeringame[2] = playeringame[3] = 0;
    respawnparm = false;
    fastparm = false;
    nomonsters = false;
    consoleplayer = 0;
    G_InitNew (d_skill, d_episode, d_map);
    gameaction = ga_nothing;
}


void
G_InitNew
( skill_t   skill,
  int       episode,
  int       map )
{
    char *skytexturename;
    int             i;

    if (paused)
    {
    paused = false;
    S_ResumeSound ();
    }

    /*
    // Note: This commented-out block of code was added at some point
    // between the DOS version(s) and the Doom source release. It isn't
    // found in disassemblies of the DOS version and causes IDCLEV and
    // the -warp command line parameter to behave differently.
    // This is left here for posterity.

    if (skill > sk_nightmare)
    skill = sk_nightmare;

    // This was quite messy with SPECIAL and commented parts.
    // Supposedly hacks to make the latest edition work.
    // It might not work properly.
    if (episode < 1)
      episode = 1;

    if ( gamemode == retail )
    {
      if (episode > 4)
    episode = 4;
    }
    else if ( gamemode == shareware )
    {
      if (episode > 1)
       episode = 1; // only start episode 1 on shareware
    }
    else
    {
      if (episode > 3)
    episode = 3;
    }
    */

    if (map < 1)
    map = 1;

    if ( (map > 9)
     && ( gamemode != commercial) )
      map = 9;

    M_ClearRandom ();

    if (skill == sk_nightmare || respawnparm )
    respawnmonsters = true;
    else
    respawnmonsters = false;

    if (fastparm || (skill == sk_nightmare && gameskill != sk_nightmare) )
    {
    for (i=S_SARG_RUN1 ; i<=S_SARG_PAIN2 ; i++)
        states[i].tics >>= 1;
    mobjinfo[MT_BRUISERSHOT].speed = 20*FRACUNIT;
    mobjinfo[MT_HEADSHOT].speed = 20*FRACUNIT;
    mobjinfo[MT_TROOPSHOT].speed = 20*FRACUNIT;
    }
    else if (skill != sk_nightmare && gameskill == sk_nightmare)
    {
    for (i=S_SARG_RUN1 ; i<=S_SARG_PAIN2 ; i++)
        states[i].tics <<= 1;
    mobjinfo[MT_BRUISERSHOT].speed = 15*FRACUNIT;
    mobjinfo[MT_HEADSHOT].speed = 10*FRACUNIT;
    mobjinfo[MT_TROOPSHOT].speed = 10*FRACUNIT;
    }

    // force players to be initialized upon first level load
    for (i=0 ; i<MAXPLAYERS ; i++)
    players[i].playerstate = PST_REBORN;

    usergame = true;                // will be set false if a demo
    paused = false;
    demoplayback = false;
    automapactive = false;
    viewactive = true;
    gameepisode = episode;
    gamemap = map;
    gameskill = skill;

    viewactive = true;

    // Set the sky to use.
    //
    // Note: This IS broken, but it is how Vanilla Doom behaves.
    // See http://doomwiki.org/wiki/Sky_never_changes_in_Doom_II.
    //
    // Because we set the sky here at the start of a game, not at the
    // start of a level, the sky texture never changes unless we
    // restore from a saved game.  This was fixed before the Doom
    // source release, but this IS the way Vanilla DOS Doom behaves.

    if (gamemode == commercial)
    {
        if (gamemap < 12)
            skytexturename = "SKY1";
        else if (gamemap < 21)
            skytexturename = "SKY2";
        else
            skytexturename = "SKY3";
    }
    else
    {
        switch (gameepisode)
        {
          default:
          case 1:
            skytexturename = "SKY1";
            break;
          case 2:
            skytexturename = "SKY2";
            break;
          case 3:
            skytexturename = "SKY3";
            break;
          case 4:        // Special Edition sky
            skytexturename = "SKY4";
            break;
        }
    }

    skytexturename = DEH_String(skytexturename);

    skytexture = R_TextureNumForName(skytexturename);


    G_DoLoadLevel ();
}


//
// DEMO RECORDING
//
#define DEMOMARKER      0x80


void G_ReadDemoTiccmd (ticcmd_t* cmd)
{
    if (*demo_p == DEMOMARKER)
    {
    // end of demo data stream
    G_CheckDemoStatus ();
    return;
    }
    cmd->forwardmove = ((signed char)*demo_p++);
    cmd->sidemove = ((signed char)*demo_p++);

    // If this is a longtics demo, read back in higher resolution

    if (longtics)
    {
        cmd->angleturn = *demo_p++;
        cmd->angleturn |= (*demo_p++) << 8;
    }
    else
    {
        cmd->angleturn = ((unsigned char) *demo_p++)<<8;
    }

    cmd->buttons = (unsigned char)*demo_p++;
}

// Increase the size of the demo buffer to allow unlimited demos

static void IncreaseDemoBuffer(void)
{
    int current_length;
    byte *new_demobuffer;
    byte *new_demop;
    int new_length;

    // Find the current size

    current_length = demoend - demobuffer;

    // Generate a new buffer twice the size
    new_length = current_length * 2;

    new_demobuffer = Z_Malloc(new_length, PU_STATIC, 0);
    new_demop = new_demobuffer + (demo_p - demobuffer);

    // Copy over the old data

    memcpy(new_demobuffer, demobuffer, current_length);

    // Free the old buffer and point the demo pointers at the new buffer.

    Z_Free(demobuffer);

    demobuffer = new_demobuffer;
    demo_p = new_demop;
    demoend = demobuffer + new_length;
}

void G_WriteDemoTiccmd (ticcmd_t* cmd)
{
    byte *demo_start;

    if (gamekeydown[key_demo_quit])           // press q to end demo recording
    G_CheckDemoStatus ();

    demo_start = demo_p;

    *demo_p++ = cmd->forwardmove;
    *demo_p++ = cmd->sidemove;

    // If this is a longtics demo, record in higher resolution

    if (longtics)
    {
        *demo_p++ = (cmd->angleturn & 0xff);
        *demo_p++ = (cmd->angleturn >> 8) & 0xff;
    }
    else
    {
        *demo_p++ = cmd->angleturn >> 8;
    }

    *demo_p++ = cmd->buttons;

    // reset demo pointer back
    demo_p = demo_start;

    if (demo_p > demoend - 16)
    {
        if (vanilla_demo_limit)
        {
            // no more space
            G_CheckDemoStatus ();
            return;
        }
        else
        {
            // Vanilla demo limit disabled: unlimited
            // demo lengths!

            IncreaseDemoBuffer();
        }
    }

    G_ReadDemoTiccmd (cmd);         // make SURE it is exactly the same
}



//
// G_RecordDemo
//
void G_RecordDemo (char *name)
{
    size_t demoname_size;
    int i;
    int maxsize;

    usergame = false;
    demoname_size = strlen(name) + 5;
    demoname = Z_Malloc(demoname_size, PU_STATIC, NULL);
    M_snprintf(demoname, demoname_size, "%s.lmp", name);
    maxsize = 0x20000;

    //!
    // @arg <size>
    // @category demo
    // @vanilla
    //
    // Specify the demo buffer size (KiB)
    //

    i = M_CheckParmWithArgs("-maxdemo", 1);
    if (i)
    maxsize = atoi(myargv[i+1])*1024;
    demobuffer = Z_Malloc (maxsize,PU_STATIC,NULL);
    demoend = demobuffer + maxsize;

    demorecording = true;
}

// Get the demo version code appropriate for the version set in gameversion.
int G_VanillaVersionCode(void)
{
    switch (gameversion)
    {
        case exe_doom_1_2:
            I_Error("Doom 1.2 does not have a version code!");
        case exe_doom_1_666:
            return 106;
        case exe_doom_1_7:
            return 107;
        case exe_doom_1_8:
            return 108;
        case exe_doom_1_9:
        default:  // All other versions are variants on v1.9:
            return 109;
    }
}

void G_BeginRecording (void)
{
    int             i;

    //!
    // @category demo
    //
    // Record a high resolution "Doom 1.91" demo.
    //

    longtics = M_CheckParm("-longtics") != 0;

    // If not recording a longtics demo, record in low res

    lowres_turn = !longtics;

    demo_p = demobuffer;

    // Save the right version code for this demo

    if (longtics)
    {
        *demo_p++ = DOOM_191_VERSION;
    }
    else
    {
        *demo_p++ = G_VanillaVersionCode();
    }

    *demo_p++ = gameskill;
    *demo_p++ = gameepisode;
    *demo_p++ = gamemap;
    *demo_p++ = deathmatch;
    *demo_p++ = respawnparm;
    *demo_p++ = fastparm;
    *demo_p++ = nomonsters;
    *demo_p++ = consoleplayer;

    for (i=0 ; i<MAXPLAYERS ; i++)
    *demo_p++ = playeringame[i];
}


//
// G_PlayDemo
//

char*   defdemoname;

void G_DeferedPlayDemo (char* name)
{
    defdemoname = name;
    gameaction = ga_playdemo;
}

// Generate a string describing a demo version

static char *DemoVersionDescription(int version)
{
    static char resultbuf[16];

    switch (version)
    {
        case 104:
            return "v1.4";
        case 105:
            return "v1.5";
        case 106:
            return "v1.6/v1.666";
        case 107:
            return "v1.7/v1.7a";
        case 108:
            return "v1.8";
        case 109:
            return "v1.9";
        default:
            break;
    }

    // Unknown version.  Perhaps this is a pre-v1.4 IWAD?  If the version
    // byte is in the range 0-4 then it can be a v1.0-v1.2 demo.

    if (version >= 0 && version <= 4)
    {
        return "v1.0/v1.1/v1.2";
    }
    else
    {
        M_snprintf(resultbuf, sizeof(resultbuf),
                   "%i.%i (unknown)", version / 100, version % 100);
        return resultbuf;
    }
}

void G_DoPlayDemo (void)
{
    skill_t skill;
    int             i, episode, map;
    int demoversion;

    gameaction = ga_nothing;
    demobuffer = demo_p = W_CacheLumpName (defdemoname, PU_STATIC);

    demoversion = *demo_p++;

    if (demoversion == G_VanillaVersionCode())
    {
        longtics = false;
    }
    else if (demoversion == DOOM_191_VERSION)
    {
        // demo recorded with cph's modified "v1.91" doom exe
        longtics = true;
    }
    else
    {
        char *message = "Demo is from a different game version!\n"
                        "(read %i, should be %i)\n"
                        "\n"
                        "*** You may need to upgrade your version "
                            "of Doom to v1.9. ***\n"
                        "    See: http://doomworld.com/files/patches.shtml\n"
                        "    This appears to be %s.";

        I_Error(message, demoversion, G_VanillaVersionCode(),
                         DemoVersionDescription(demoversion));
    }

    skill = *demo_p++;
    episode = *demo_p++;
    map = *demo_p++;
    deathmatch = *demo_p++;
    respawnparm = *demo_p++;
    fastparm = *demo_p++;
    nomonsters = *demo_p++;
    consoleplayer = *demo_p++;

    for (i=0 ; i<MAXPLAYERS ; i++)
    playeringame[i] = *demo_p++;

    if (playeringame[1] || M_CheckParm("-solo-net") > 0
                        || M_CheckParm("-netdemo") > 0)
    {
    netgame = true;
    netdemo = true;
    }

    // don't spend a lot of time in loadlevel
    precache = false;
    G_InitNew (skill, episode, map);
    precache = true;
    starttime = I_GetTime ();

    usergame = false;
    demoplayback = true;
}

//
// G_TimeDemo
//
void G_TimeDemo (char* name)
{
    //!
    // @vanilla
    //
    // Disable rendering the screen entirely.
    //

    nodrawers = M_CheckParm ("-nodraw");

    timingdemo = true;
    singletics = true;

    defdemoname = name;
    gameaction = ga_playdemo;
}


/*
===================
=
= G_CheckDemoStatus
=
= Called after a death or level completion to allow demos to be cleaned up
= Returns true if a new demo loop action will take place
===================
*/

boolean G_CheckDemoStatus (void)
{
    int             endtime;

    if (timingdemo)
    {
        float fps;
        int realtics;

    endtime = I_GetTime ();
        realtics = endtime - starttime;
        fps = ((float) gametic * TICRATE) / realtics;

        // Prevent recursive calls
        timingdemo = false;
        demoplayback = false;

    I_Error ("timed %i gametics in %i realtics (%f fps)",
                 gametic, realtics, fps);
    }

    if (demoplayback)
    {
        W_ReleaseLumpName(defdemoname);
    demoplayback = false;
    netdemo = false;
    netgame = false;
    deathmatch = false;
    playeringame[1] = playeringame[2] = playeringame[3] = 0;
    respawnparm = false;
    fastparm = false;
    nomonsters = false;
    consoleplayer = 0;

        if (singledemo)
            I_Quit ();
        else
            D_AdvanceDemo ();

    return true;
    }

    if (demorecording)
    {
    *demo_p++ = DEMOMARKER;
    M_WriteFile (demoname, demobuffer, demo_p - demobuffer);
    Z_Free (demobuffer);
    demorecording = false;
    I_Error ("Demo %s recorded",demoname);
    }

    return false;
}



